The present invention is directed toward improvements in indirect fired, vented air heaters.
There are generally two categories of gas-fired heaters, direct-fired and indirect-fired (or vented) heaters. With a direct-fired heater, the products of combustion are released into the heated space. With an indirect-fired heater, some form of heater exchanger is used to transfer the heat from the combustion gases to the heated space. The combustion gases are vented out of the heated area.
Gas-fired heaters used in temporary heating applications, such as on construction sites, have generally been of the direct-fired type. There is currently an increasing demand for indirect-fired heaters for such applications. There is also an increasing demand for more energy efficient heaters. As a rule, heaters of higher efficiency are also much larger in size. The challenge is to have a relatively small yet efficient heater that can be used in temporary applications. Since temporary heaters are used seasonally, a smaller size would provide the benefit of reduced costs for off-season storage.